Start by mashing the plantains to make sure they are mashed. You can do this with a fork or a blender.

Mix them with flour and milk until they have the consistency of a thick dough.

Set the beans aside in another bowl. 

Take some of the plantain dough to give it a flat, circular shape. Then add a little bit of the beans in the middle and wrap them with the same dough to seal the empanadas.

Repeat the process until you make as many empanadas as you want.

In a frying pan with hot oil, fry the empanadas until golden brown.

Serve them on a plate and add a little sugar on top to decorate them.